Many devices have been described which may be used to carry out detection assays such as diagnostic immunoassays. Some of these devices are based on the principle of lateral flow, that is, the flow of a liquid along a solid phase by capillary and other forces.
Examples of prior art patents include U.S. Pat. Nos. 4,943,522, 5,427,739, 5,602,040, 6,485,982, 6,555,390, 6,565,808 and WO 94/29696.